From 4329de41e30570f2e5702be63234de03fcbbd20f Mon Sep 17 00:00:00 2001
From: c vw <dl1ycf@darc.de>
Date: Tue, 30 Mar 2021 17:38:43 +0200
Subject: [PATCH] Modification that allows using a "voice keyer" with radios
 that have a microphone jack.

---
 new_protocol.c | 11 ++++++++++-
 old_protocol.c | 14 +++++++++++++-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/new_protocol.c b/new_protocol.c
index 2066e8f..41cbb9b 100644
--- a/new_protocol.c
+++ b/new_protocol.c
@@ -1956,7 +1956,16 @@ static void process_mic_data(int bytes) {
   for(i=0;i<MIC_SAMPLES;i++) {
     sample=(short)(buffer[b++]<<8);
     sample |= (short) (buffer[b++]&0xFF);
-    fsample = transmitter->local_microphone ? audio_get_next_mic_sample() : (float) sample * 0.00003051;
+    //
+    // If PTT comes from the radio, possibly use audio from BOTH sources
+    // we just add on since in most cases, only one souce will be "active"
+    //
+    if (local_ptt) {
+      fsample = (float) sample * 0.00003051;
+      if (transmitter->local_microphone) fsample +=  audio_get_next_mic_sample();
+    } else {
+      fsample = transmitter->local_microphone ? audio_get_next_mic_sample() : (float) sample * 0.00003051;
+    }
     add_mic_sample(transmitter,fsample);
   }
 }
diff --git a/old_protocol.c b/old_protocol.c
index 47cb757..7a3e929 100644
--- a/old_protocol.c
+++ b/old_protocol.c
@@ -1318,7 +1318,19 @@ static void process_ozy_byte(int b) {
       mic_sample|=(short)(b&0xFF);
       mic_samples++;
       if(mic_samples>=mic_sample_divisor) { // reduce to 48000
-        fsample = transmitter->local_microphone ? audio_get_next_mic_sample() : (float) mic_sample * 0.00003051;
+        //
+        // if local_ptt is set, this usually means the PTT at the microphone connected
+        // to the SDR is pressed. In this case, we take audio from BOTH sources
+        // then we can use a "voice keyer" on some loop-back interface but at the same
+        // time use our microphone.
+        // In most situations only one source will be active so we just add.
+        //
+        if (local_ptt) {
+          fsample = (float) mic_sample * 0.00003051;
+          if (transmitter->local_microphone) fsample += audio_get_next_mic_sample();
+        } else {
+          fsample = transmitter->local_microphone ? audio_get_next_mic_sample() : (float) mic_sample * 0.00003051;
+        }
         add_mic_sample(transmitter,fsample);
         mic_samples=0;
       }
-- 
2.45.2